Mechanical Technology January 2016

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12 Mechanical Technology — January 2016
⎪ Power transmission, bearings, bushes and seals ⎪
Over the past three years,
Metso has worked in close
collaboration with CMD and
Ferry Capitain to develop a
new high-powered mill drive solution for
large SAG and ball mills in the mining
industry. After exhaustive design research
that concluded with build, installation
and continuous full-scale testing op-
erations, Metso has now introduced its
QdX4 Mill Drive.
This system was tested for over three
million cycles at 28 MW (2×14 MW)
with an input speed of 320 rpm, proving
the torque splitting system arrangement.
In the past, grinding mills operating be-
tween 18 and 28 MW required a large
electrical wrap-around motor, known as
a gearless mill drive (GMD). The Metso
QdX4 Mill Drive system is an alternative
option to the GMD. Until now, the gear-
driven solution for large SAG and ball
mills was limited to 18 MW.
Responding to the needs of
industry
“Traditionally, the mining industry
has been somewhat reluctant to
change, but change has oc-
curred nonetheless and the
industry is now encour-
aging innovations to
operate in a more
efficient way.
Our goal
New mill drive system for
improved efficiencies
Metso’s QdX4 Mill Drive system rearranges
the dual pinion arrangement into a quad
system that equally divides input power from
two load-sharing motors into four pinions.
Metso’s new mill drive
uses traditional engi-
neering load distribution
calculations for sizing
standard base-plates
and hold-down anchor
bolts, very similar
to that seen with
dual-pinion drive
arrangements.
Metso’s latest innovation, the Metso QdX4 Mill Drive system is mooted to
help customers achieve high efficiencies in mining operations.
was to design a robust, reliable, cost-
effective, high-powered mechanical
solution without compromising the
high design standards we are all used to
seeing in our customers’ specifications,”
says Frank Tozlu, product manager
of large grinding mills at Metso
Minerals’ grinding headquarters,
in York, Pennsylvania.
“SAG and ball mill
specifications have
been developed over
many decades and we
are still developing them
today. We must continue to
look at advancing innovative
ideas through our standards and
practices when expanding upon trans-
mittable mechanical power,” he adds.
Taking architecture to the next
level
The Metso QdX4 Mill Drive system
provides the next step in the evolution
of mechanical mill drive architecture.
The progression from a single- to a dual-
pinion arrangement has been
a way to transmit twice
as much power in the
past. “We have sim-
ply rearranged the
dual system into
a quad system that equally divides input
power from two load-sharing motors into
four pinions,” Tozlu explains. With this
architecture, the Metso QdX4 is capable
of delivering up to 32 MW to horizontal
mill comminution systems.
Driving time and cost
efficiencies
The QdX4 Mill Drive has many fea-
tures that help customers achieve
both time and cost efficiencies
from an equipment point of view
and in terms of the overall costs
of a large-scale operation. For
example, two installed QdX4 drive
units weigh less than one GMD
quarter section. This significantly
reduces transportation cost, de-
livery time, equipment handling
and site preparation. The system
also reduces the need for massive
reinforced foundation volumes
and the requirement for customers
to install large crane capacities.
Similarly, there is no need for ex-